Up to now, in the case where a plurality of elevators are provided together, those elevators are operated under group control. An assigning system is applied as one of group-managed operation, in which an assignment evaluation value is arithmetically operated for each elevator cage immediately after an elevator hall call is registered, and the evaluation value is assigned to the best elevator cage as a cage to be served so that only the cage to be assigned is responsive to the elevator hall call.
Furthermore, there are the following group managing systems that are made to improve the running efficiency and to reduce a waiting period on the elevator hall.
(a) As disclosed in Japanese Patent Unexamined Publication No. Hei 7-247066, in order to reduce the number of states where the elevator is not waiting on a reference floor, a departure time interval at which the elevator departs from the reference floor is controlled.
(b) As disclosed in Japanese Patent Unexamined Publication No. Hei 5-139635, the return of the elevator to the reference floor and dispersive waiting are employed together to control the elevator such that the services of the transportation from the reference floor and the transportation between the floors are improved.
However, the above-described prior art suffers from the following problems.
First, the prior art disclosed in Japanese Patent Unexamined Publication No. Hei 7-247066 is effective in the case where floors high in frequency of use at the time of attending and leaving office, etc., can be specified. However, since only the known specified floors are not always confused, it is not effective in other cases.
Second, the prior art disclosed in Japanese Patent Unexamined Publication No. Hei 5-139635 conducts only the waiting operation on the reference floor (specified floor) and the specified floor other than the reference floor regardless of the frequency of use on each floor. Thus, because the service other than the specified floors is not considered, if a waiting mode on the specified floors is entered, the service on the floors other than the specified floors is further degraded.
Therefore, the present invention has been made to solve the above-described problems, and an object of the present invention is to provide an elevator control apparatus which is capable of improving the services of the entire elevator system by unifying the service on each floor and performing group management control with more efficiency.